     ;; vary-meta
     (is (= {:a 1} (meta (vary-meta [] assoc :a 1))))
     (is (= {:a 1 :b 2} (meta (vary-meta (with-meta [] {:b 2}) assoc :a 1))))
+    ;; comparator
+    (is (= [1 1 2 2 3 5] (seq (.sort (to-array [2 3 1 5 2 1]) (comparator <)))))
+    (is (= [5 3 2 2 1 1] (seq (.sort (to-array [2 3 1 5 2 1]) (comparator >)))))
+    (is (= (hash 'foo) (hash (symbol "foo"))))
+    (is (= (hash 'foo/bar) (hash (symbol "foo" "bar"))))
+    (is (= (lazy-cat [1] [2] [3]) '(1 2 3)))
     ))
 
 (deftest test-booleans

    (is (= (count (range 0 0 0)) 0))
    (is (= (take 3 (range 1 0 0)) (list 1 1 1)))
    (is (= (take 3 (range 3 1 0)) (list 3 3 3)))
    ))

(deftest test-sorted-map

      (is (every? true?
            (for [not-m [[] 1 "asdf" :foo]]
              (not (my-map? not-m)))))
      ;; multimethod hashing
      (is (= foo2' (ffirst {foo2' 1})))
)))

(deftest test-range
